Mushroom sizing is the separation of fruiting bodies by cap diameter using rollers, belts or sieves so that processing batches and retail packs meet uniform grade requirements.
In trade practice
At the packhouse, operators calibrate roller or sieve gaps to the cap-diameter ranges stated in the buyer’s specification before each production run. Sized lots are labelled with the grade name and checked against reference samples. A common error is mixing grades when throughput pressure is high, which causes non-conformance claims on arrival. For dried mushrooms, sizing is repeated after drying because shrinkage alters diameter.
In a specification
A purchase specification typically states cap-diameter ranges in millimetres for each named grade, along with the maximum percentage of off-size pieces permitted per lot.